We have shown that the host chaperone molecules are redirected during Herpes Simplex Virus Type-1 (HSV-1) infection. In the HSV-1-infected cell, we found the cellular chaperone machinery (Hsp90, Hsp70 and Hsp40) is localized at virus-specific sites and may be in an activated' state similar to that found in tumor tissues. This activated chaperone complex is the known target of Hsp90- inhibitor molecules. Preliminary studies suggest that inhibitors of Hsp90 block HSV-1 infection very early in infection, prior to DNA synthesis. This proposal describes experiments to test the hypothesis that in the virus-infected cell, the chaperone machinery is in an activated state similar to that found in tumor tissues and that this complex represents a novel antiviral target. Specific Aim 1 will identify the viral proteins that interact with Hsp90 using a proteomic approach including 2D-gel electrophoresis and tandem mass spectroscopy. Specific Aim 2 will test the hypothesis that Hsp90 is required for efficient HSV-1 DNA replication by isolating resistance mutants to Hsp90-inhibitors. The studies described herein will not only provide information about the basic biology of chaperone-directed processes occurring in the HSV-1-infected cell, but also impart knowledge about the new frontier of antiviral chemotherapeutics that target the host-pathogen interface. [unreadable] [unreadable]